Electromechanical command devices are widely used to operate and control machines and plants. They come in various forms, e.g. as pushbuttons, knob-operated switches, key switches or emergency stop switches. Command devices are mounted on switchboards, operating panels, switchgear cabinet doors or housing covers. Manual actuation of the command devices causes changes to electric switching states, thereby producing the desired control effects. Command devices are equipped as standard with a mechanical display to display prevailing switching states, the mechanical display in some instances being equipped alternatively or additionally with an illuminable or illuminated unit.
The requirement for an integrated visual display, which is both a mechanical and/or electrical switching display, poses the problem of accommodating the necessary components, as the overall volume of the device can only vary within narrow limits, in particular due to a standard installation diameter (e.g. 22.5 mm). Until now, when it was not possible to integrate the display in the command device, an additional command point, for example with an indicator light, was generally attached. The additional space requirement, for example on a switchboard of the installation unit, and the necessary use of a separate display make this solution disadvantageous.
A mechanical display for emergency stop mushroom heads is known from previous solutions and converts a linear actuation movement to a movement of a display element. However the deflection of the movement of the display element is limited, as the space requirement of the display mechanism would otherwise be too great.